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2005 Aug 27
1
survival parametric question
...ee" the accelerating-decelerating effect in the AFT case. In addition how can simulate a model in the AFT case ( some examples of simulation are given in the design manual for the COX-PH case. I hope that my questions are not borring, if so sory I am a new user of R package. Best regards D.Lalountas University of Patras , Greece --------------------------------- [[alternative HTML version deleted]]
2007 Jun 28
0
WEIBULL FRAILTY MODEL HELP
...eto^(p[2]-1))/p[1]))*stat lik <- p[3]*log(p[3])-log(gamma(p[3]))+sum(lnhaz)+ log(gamma(di+p[3]))-(p[3]+di)*log(p[3]+cumhaz) -2*lik } di <-sum(stat) initial<-c(500000,2.8,.5,1.8) # initial 1/exp(constant) t<-nlm(likelihood.weibul,initial,print.level=1,hessian=T) Best Regards, Denis Lalountas University of Patras insem<-read.table("Melanoma.txt",header=T) id <- insem$id timeto<-insem$time stat<-insem$status x1<-insem$ulcer x2 <-insem$thickness x2 <- log(x2) id time status sex age year thickness ulcer 1 1 10 0 1 76 1972 6.76...